1,1-bis-(4-(1&#39;-benzyl-3&#39;-methyl-pyrazalone-azo)phenyl)cyclohexane

ABSTRACT

A WATER-INSOLUBLE DIAZO DYESTUFF PARTICULARLY ADVANTAGEOUS IN THE DYEING OF INKS AND PASTES FOR BALL POINT PENS IS PRODUCED BY COUPLING 1-BENZYL-3-METHYL-PYRAZOLONE WITH 1,1-BIS-(4-AMINOPHENYL)CYCLOHEXANE.

United States Patent 5 Int. C1. C09!) 31/14; C09d 11/16, 11/18 US. Cl. 260-160 1 Cla ABSTRACT OF THE DISCLOSURE A water-insoluble diazo dyestuif particularly advantageous in the dyeing of inks and pastes for ball point pens is produced by coupling 1-benzyl-3-methyl-pyrazolone with 1,1-bis-(4-aminophenyl)cyclohexane.

The present invention is concerned with the waterinsoluble disazo dyestuff of the formula and a process for its production.

The dyestuff of the above mentioned formula is obtained by coupling tetrazotized 1,1-bis-(4'-aminophenyl)- cyclohexane with 1-benzy1-3-methyl-pyrazolone in known manner, preferably in aqueous solution or suspension at temperatures of about 0-10 C. After coupling the dyestuff may be separated from the reaction mixture by filtration.

The starting component 1-benzyl-3-methyl-pyrazolone- 5 is a known substance and may be obtained for example by reacting benzylhydrazine with acet acetic acid ethyl ester as described by Curtius in Journal fiir praktische Chemie, 2, 85, page 50 or in the German patent specification 1,003,215.

The starting component 1,1-bis-(4'-aminophenyl)cyclohexane is known too and may be prepared by condensation of aniline with cyclohexanone.

3,577,403 Patented May 4, 1971 The new yellow disazo dyestuif is excellently soluble in organic solvents as for example alcohols such as benzyl alcohol and is suitable for the dyeing of inks and pastes for ball point pens.

The parts given below are parts by Weight.

Example A tetrazo solution prepared in conventional manner from 23.2 parts of 1,1-bis-(4-aminophenyl)cyclohexane is introduced at 5 C. in a solution of 1-benzyl-3-methylpyrazolone-S prepared in the following manner: 33.3 parts of the pyrazolone compound are dissolved at C. in 300 parts of Water containing 28 parts of sodium carbonate and purified with the aid of charcoal. After the addition of suflicient ice to hold a temperature of 5 C. the reaction mixture is stirred for /2 hour. The precipitated dyestuif is filtered off with suction, washed with water (free from calcium carbonate and salts) and dried at 50 C. There are obtained 47.5 parts of a dyestulf which is highly soluble in hydrocarbons, benzyl alcohol, esters, fatty oils and paraflines with a yellow shade and which may be used for dyeing pastes for ball point pens.

We claim:

1. A Water-insoluble disazo dyestufi of the formula on; N:NVN=N CH:

\N OH HO N/ +Hz (1111 References Cited UNITED STATES PATENTS 1,233,742 7/1917 Anderwert et al 260- 1,819,957 8/1931 Krebser et a1 260-160X 1,838,235 12/1931 Schule et al. 260-160X 2,241,795 5/1941 Taube et a1. 260-160X 3,124,566 3/1964 Jung et a1. 260-160 3,313,799 4/1967 Noll 260-160 FLOYD DALE HIGEL, Primary Examiner US. Cl. X.R. 

